docs: update overlay and progress example (#3887)

Author: snitin315

examples/client/overlay/README.md

@@ -19,6 +19,12 @@ Usage via CLI:
 npx webpack serve --open --client-overlay
 ```
 
+To disable:
+
+```shell
+npx webpack serve --open --no-client-overlay
+```
+
 ## What Should Happen
 
 1. The script should open `http://localhost:8080/` in your default browser.

examples/client/overlay/webpack.config.js

@@ -8,4 +8,9 @@ module.exports = setup({
   context: __dirname,
   // create error for overlay
   entry: "./invalid.js",
+  devServer: {
+    client: {
+      overlay: true,
+    },
+  },
 });

examples/client/progress/README.md

@@ -19,6 +19,12 @@ Usage via CLI:
 npx webpack serve --open --client-progress
 ```
 
+To disable:
+
+```shell
+npx webpack serve --open --no-client-progress
+```
+
 ## What Should Happen
 
 1. The script should open `http://localhost:8080/` in your default browser.

examples/client/progress/webpack.config.js

@@ -7,4 +7,9 @@ const { setup } = require("../../util");
 module.exports = setup({
   context: __dirname,
   entry: "./app.js",
+  devServer: {
+    client: {
+      progress: true,
+    },
+  },
 });